RU-2861317-C1 - METHOD FOR PHOTODYNAMIC DESTRUCTION OF BIOFILMS OF GRAM-NEGATIVE AND GRAM-POSITIVE BACTERIA

RU2861317C1RU 2861317 C1RU2861317 C1RU 2861317C1RU-2861317-C1

Abstract

FIELD: medicine; microbiology. SUBSTANCE: invention can be used to optimise treatment regimens for diseases associated with the formation of biofilms by microorganisms, including chronic inflammatory processes. For this purpose, biofilms are treated for 10-15 minutes with methylthioninium chloride in the form of an aqueous solution at a concentration of 0.05 to 0.2%, followed by exposure to laser radiation with a wavelength of 662 nm. The radiation dose is 4.75 J/cm 2 , the power density is 14.4 mW/cm 2 . The exposure is performed twice with an interval of 60 minutes. EFFECT: complete degradation of a multilayer mature biofilm of both gram-positive and gram-negative bacteria down to single cells devoid of extracellular matrix, which can be used to optimise treatment regimens for diseases associated with the formation of biofilms by microorganisms, including chronic inflammatory processes. 1 cl, 6 dwg, 3 ex

Inventors

Kryazhev Dmitrij Valerevich
Ermolina Galiya Barievna
BELYAEVA ELENA VYACHESLAVOVNA
Streltsova Olga Sergeevna
Elagin Vadim Vyacheslavovich
IGNATOVA NADEZHDA IVANOVNA

Dates

Publication Date: 20260504
Application Date: 20250908

Claims (1)

A method for photodynamic destruction of biofilms of gram-positive and gram-negative microorganisms, including sensitization with methylthioninium chloride and exposure to laser radiation, characterized in that methylthioninium chloride is used in the form of an aqueous solution at a concentration of 0.05 to 0.2% for 10-15 minutes, followed by exposure to laser radiation with a wavelength of 662 nm, a dose of 4.75 J/ cm2 , and a power density of 14.4 mW/ cm2 in two repetitions with an interval of 60 minutes.

Description

The invention relates to microbiology and medicine, concerns a method for photodynamic destruction of biofilms of gram-negative and gram-positive bacteria and can be used to optimize treatment regimens for infectious diseases caused by microorganisms in the form of biofilms, including chronic inflammatory processes. Among all infectious lesions, approximately 65-80% are caused by bacteria that form biofilms [Khmel I.A. Bacterial biofilms and associated difficulties in medical practice. URL: https://img.ras.ru/files/center/biofilms.doc, date of access 08/09/2021.]. For example, biofilms formed by Staphylococcus epidermidis and Escherichia coli microorganisms usually cause intravascular catheter-associated infection, and Staphylococcus aureus biofilms cause infections developing on metal implants [E. Barth, Q.M. Myrvik, W. Wagner, A.G. Gristina, In vitro and in vivo comparative colonization of Staphylococcus aureus and Staphylococcus epidermidis on orthopaedic implant materials//Biomaterials. - 1989. Vol.10. No.5. - P.325-328.; J. Dankert, A.H. Hogt, J. Feijen, Biomedical polymers: bacterial adhesion, colonization, and infection//Crit. Rev. Biocompat. - 1986. №2. - P.219-301.]. Many chronic infections (lung, ear, wound), as well as infections associated with the use of medical implantable equipment - lenses, catheters, prostheses, artificial heart valves - are caused by bacteria growing in the form of biofilms [Costerton JW, Geesey GG, Cheng KJ. How bacteria stick// Sci. Am. - 1978. Vol.10. №5. №.238. - P.86-95.; Jamal M, Ahmad W, Andleeb S, Jalil F, Imran M, Nawaz MA, et al. Bacterial biofilm and associated infections// J Chin Med Assoc. - 2018. №. 81. - P.7-11.; Hall MR, Mc Gillicuddi E, Kaplan LJ. Biofilm: basic principles, pathophysiology, and implications for clinicians// Surg Infect (Larchmt.). - 2014. Vol.15. №1 - P.1-7.]. In patients with chronic wound infections, about 60% of cases are associated with biofilm formation. Bacterial colonization in patients with intravenous catheters, endotracheal tubes, and urethral catheters is observed during the first 10-14 days after their installation. A biofilm is a structurally organized community of microorganisms enclosed within a polymer matrix synthesized by community members and attached to biotic and abiotic surfaces. The matrix protects microorganisms from external factors, including environmental factors and factors of the body's immune defense. The presence of a matrix hinders the penetration of antimicrobial agents into biofilms and protects biofilm bacteria from human leukocytes [Hall CW, Mah T-F. Molecular mechanisms of biofilm-based antibiotic resistance and tolerance in pathogenic bacteria// FEMS Microbiol Rev. 2017. Vol. 41. №3. - P. 276-301.; Jakobsen TH, Tolker-Nielsen T, Givskov M. Bacterial biofilm control by perturbation of bacterial signaling processes// Int J Mol Sci. - 2017. Vol. 18. №9 - P. 1970.; Flemming HC, Neu TR, Worniak DJ. The EPS matrix: the «house of biofilm cells»//J. Bacteriol. - 2007.Vol.189. №22. - P.7945-7947.]. The matrix is the most important component of the biofilm, constituting 85% of its volume. It is able to dynamically modulate the delivery of nutrients and oxygen to the cells inside the biofilm. This leads to a slowdown in the growth and division of bacteria, which makes these bacteria less sensitive to antibiotics compared to rapidly dividing cells. One of the promising methods of combating biofilms is the disruption of their structural integrity and disorganization, followed by the release of bacteria available for antibacterial action by biocidal drugs or antibiotics. Currently, various methods for the destruction of biofilms are known, for example, methods for the destruction of bacterial biofilms using enzymes capable of degrading matrix polysaccharides [T.S. Ilyina, Yu.M. Romanova Bacterial biofilms: role in chronic infectious processes and the search for means to combat them // Molecular Genetics, Microbiology and Virology - 2021. - No. 2. - P. 14-24.] The main disadvantage of these methods is that the enzymes are highly specific with respect to the substrate: each enzyme catalyzes a single reaction or a group of reactions of one type. Moreover, it is known that the composition of the biofilm matrix includes not only various types of polysaccharides, such as dextran, hyaluronic acid, cellulose, etc., but also other chemical components, the quantitative and qualitative composition of which can vary greatly. Methods for destroying bacterial biofilms are also known, which involve exposing them to antimicrobial peptides [RU 2664708, dated August 21, 2018]. However, peptides exhibit cytotoxicity towards mammalian cells, lose activity at low salt concentrations or in the presence of plasma proteins, and are degraded by tissue proteases. There are also known methods for destroying bacterial biofilms by photodynamic therapy (PDT) using photosensitizers (PS), which, when exposed to visible or infrared light with wavel